How to Assign Constraints in Gator Queries
Gator provides "Low Limit" and "Up Limit" text fields to specify constraints on a specific query. The formatting rules used in setting these constraints depend on the datatype, as follows:
A character string must be enclosed in a pair of quote; e.g. in "lower limit" or "upper limit" text fields, type in one of the following:
If the quotes are missing, a syntax error like this will be returned:
201: A syntax error has occurred. Use only single quotes when specifying strings. Double quotes may cause the query to fail.
Character data types follow the C convention in interpreting constraints. Check the column description of character datatypes to ensure that meaningful constraints are input.
Example: the MSX6C catalog includes a source name field, called "name", encoded on the basis of the galactic position of the source; e.g. G090.5476+07.9157 is at l=90.5476 and b=+07.9157 in galactic coordinates. Entering this constraint in the upper or lower limit field:
will retrieve all sources with the name G090.5476+07.9157.
But entering this constraint on the lower limit field:
will retrieve all sources with galactic longitudes of greater than 90.4576 degrees.
Numerical (Integer, Float, or Decimal)
Databases generally support a different range of datatypes than do the programming languages with which many users will be familiar. Use the following formatting rules in supplying constraints:
- Treat int and smallint datatypes as integers
- Treat float and smallfloat datatypes as floats.
- Treat decimal datatypes as doubles.
- =2 (for integer)
- >=2.543 (for float or decimal)
Gator supports the yyyy-mm-dd format for date datatypes for most catalogs. For example:
If this format does not work for your query, please contact the IRSA HelpDesk.